Ch.11, Somato Continued

Question 1

where is the vestibular system for balance located

Answer 1

inner ear

Question 2

difference in function between semiciercular canals and otolith organs

Answer 2

semicircular: detect head ROTation
OTOLITH: sense body’s position in relation to gravity (tilting of head) and liner acceleration

Question 3

2 parts of the otolith organs and location, function

Answer 3

utricle and saccule, linear acceleration/gravityt
part of the semicircular canals in inner ear
macula of utricle/macula utriculi: horizontally oriented, detects forward and back option
macula of saccula/ macula sacculi: vertically oriented: detects gravitational force

Question 4

cranial nerve #8 other names and function

Answer 4

auditory nerve or vestibular cochlear nerve
sends VESTIBULAR INFO TO THE CNS

Question 5

crista ampullaris

Answer 5

part of the semicircular canals of the inner ear

Question 6

angular acceleration

Answer 6

rotation of head/rate of head rotation
semicircular canals respond to this

Question 7

5 components of the crista ampullaris

Answer 7

1. cupula:
2. endolymph: fluid, goes in the opposite direction of head motion
3. Hair cells: cilia bend on these ikn the same principle; are embedded in the cupula
4. Supporting cells
5. Sensory nerve fibers

Question 8

Cupula function and location

Answer 8

part of the crista ampullaris; semicircular canals
RESPOND TO HEAD ROTATION
The cupula itself is the gelatinous component of the crista ampullaris that extends from the crista to the roof of the ampullae. When the head rotates, the endolymph filling the semicircular ducts initially lags behind due to inertia. As a result, the cupula is deflected opposite the direction of head movement.

Question 9

stereocilia, definition

Answer 9

Stereocilia are tiny, hair-like projections on the surface of sensory cells in the inner ear that are essential for hearing and balance

Question 10

3 states of stereocilia

Answer 10

1. Channels Open: stereocilia move toward the tallest one = receptor potential = net depolarization = NT release onto sensory neurons
2. Resting State: catanions are still leaking into the cell and NT is leaking out
3. Hyperpolarization: movement toward shortest

Question 11

otoliths location and function

Answer 11

crystals of calcium carboinate that add weight onto the membrane Otoliths help you stay upright and balanced: location relative to gravity. When you tilt your head, the otoliths move relative to the hair cells in your inner ear, which sends information to your brain about your head’s position and motion.
Otoliths detect linear acceleration, or changes in speed in a straight line, such as when you fall, take an elevator, or brake in a car/ decceleration.

Question 12

macula

Answer 12

Each otolith organ houses a structure called the macula. The macula includes hair cells that extend into a gelatin-like substance that’s filled with calcium crystals. When you’re in motion, the crystals inside your otolith organs shift. This causes the hair cells to shift, as well. This shearing triggers the release of nerve signals that travel to your brain.

Question 13

HOW DOES endolymph influence stereocilia?

Answer 13

sends information about the plane of movement and causes it to move

Question 14

why does the endolymph fluid move in the opposite direction of the head at first?

Answer 14

lags behind bc of intertia

Question 15

does the cochlea have a role in the vestibular system

Answer 15

no

Question 16

3 semicircular canals

Answer 16

lateral, anterior, posterior

Question 17

where are the hair cells of the utricle located?

Answer 17

in the otolithic membrane